The present invention relates to ceramic compositions using silsesquioxanes as a sintering agent, and being suitable as ceramic substrates and cements.
Synthesis of ceramics require high temperatures and long reaction times. For example, in the formation of cordierite bodies, plasticized mixtures of raw materials and organic additives are fired at temperatures of up to 1450° C.-1550° C. for 20 to 200 hours.
Lowered processing temperatures and times are desirable to avoid expenditure of extra energy and added cost. This is particularly true in the formation of monolith honeycomb structures, such as cordierite honeycombs used in treatment applications for automotive and diesel exhaust.
Cordierite coldset cement (a mixture of ground cordierite, binder, silica, and cement) is currently used to form the exterior skin of cordierite substrates. Advantageous from a low processing temperature aspect, it is incompatible with some coating processes and chemistries. For example, excessive cordierite skin or coating cracking or spalling during subsequent calcinations steps has been observed.
It would be considered an advancement in the art to provide ceramic compositions from commonly available inorganic raw-materials that can be processed at low temperatures and have high strength, which can also be used in the manufacturing of monolithic substrates or as a cement mixtures for substrate skin formation.